Retractable needle medical device

ABSTRACT

A catheter insertion device is provided that includes an insertion needle that is retractable into the device after use to prevent exposure to the contaminated needle. The needle retainer releasably retains the needle in an extended position against the bias of the biasing element. When the catheter is removed from the insertion device, the needle retainer automatically releases the needle, which is propelled rearwardly into the device. A device for inserting a guide wire into a patient is also provided. The device includes an insertion needle that is retractable into the housing of the device after use. A needle retainer releasably retains the needle in an extended position against the bias of the biasing element. The needle retainer engages the guide wire so that when the guide wire is removed from the insertion device, the needle retainer automatically releases the needle, which is propelled into the device.

FIELD OF INVENTION

The present invention relates to needle-bearing medical devices used,for example, to insert catheters or guide wires into blood vessels ofpatients. More specifically, the invention relates to such a devicehaving a retractable needle feature for rendering the devicenon-reusable and safely disposable.

BACKGROUND

Various types of medical devices employed a needle for piercing the skinof a patient for diagnostic or therapeutic purposes. One such device isan intravenous catheter insertion device for positioning a needlemounted catheter into a patient's blood vessel. Another such device isthe device for introducing a guidewire into a patient. The guidewire isthen used to guide a catheter into the patient. Once the guidewire orcatheter is properly positioned, the catheter insertion device iswithdrawn leaving the guidewire or catheter in place in the bloodvessel. Handling of such medical devices after the needle is withdrawnfrom the patient can result in transmission of various pathogens, mostnotably human immune virus (HIV), due to in inadvertent needle stick tomedical personnel.

Since the mid-1980s, concern over the risk of accidental needle stickinjuries has spawned a number of design approaches for safety needledevices. Such devices can be broadly categorized as either slidingsheath needle devices, wherein a physical barrier is positioned over theneedle tip after use or as devices with needle retraction, wherein theexposed portion of the needle is retracted into the device after use.The latter category of needle retraction devices can be furthersubdivided into manual and semiautomatic retraction devices. Manualretraction devices, as exemplified by U.S. Pat. No. 4,026,287 to Haller,U.S. Pat. No. 4,592,744, to Jagger, U.S. Pat. No. 4,808,169 to Haber andU.S. Pat. No. 5,067,490 to Haber, require the user to pull or slide aneedle-connected mechanism rearwardly to retract the needle into thedevice. In semiautomatic needle retraction devices, a biasing member,such as a spring, may be employed to push or pull the needle into thedevice in response to activation by the user of a release mechanism.Such devices are exemplified by U.S. Pat. No. 4,813,426 to Haber et al.and U.S. Pat. No. 5,125,414 to Dysarz.

U.S. Pat. No. 4,747,831 of Kulli and U.S. Pat. No. 4,900,307 of Kullishow respective catheter insertion devices and syringes withsemiautomatic needle retraction. The retraction mechanism shown in thelast-mentioned two patents are disclosed to be actuable by the user upondepression of a release button after the catheter is removed from theinsertion device or the needle is removed from the patient.

The prior art semiautomatic devices require manual actuation by theoperator. In many situations, such as an emergency situation, theoperator is distracted or rushed so that the manual step necessary toeffectuate retraction is not performed, either intentionally orunintentionally. In such instances, the used needle remains exposed,creating a risk of an inadvertent needle stick. Therefore, it would bedesirable to provide an automatic needle retraction mechanism in whichneedle retraction is effectuated by normal operation of inserting thecatheter into the patient, without the need to perform a separate manualstep. It is further desirable to provide a device with a limited numberof components so that the device can be produced cost effectively.

SUMMARY OF INVENTION

With the foregoing in mind, the present invention provides a medicaldevice having a hollow housing and a catheter mounted on the housing.The device includes a needle operable between an extended positionextending forwardly from the housing and a retracted position in whichthe needle is enclosed in the housing. A biasing element biases theneedle toward the retracted position. A needle retainer is fixedlyconnected with the needle. The needle retainer releasably retains theneedle in the extended position against the bias on the biasing element.The needle retainer preferably comprises an elongated arm having afollower portion engaging the catheter. Upon removal of the catheterfrom the housing, the catheter disengages the follower portion, therebyallowing the needle retainer to release the needle. The biasing elementthen propels the catheter rearwardly into the housing.

The present invention also provides a medical device having a hollowhousing and a needle for inserting a guidewire. The device includes aneedle operable between an extended position extending forwardly fromthe housing and a retracted position in which the needle is enclosedwithin the housing. A biasing element biases the needle toward theretracted position. The device includes a needle retainer operablebetween a first position in which the needle retainer releasably engagesthe needle against the rearward bias of the biasing element, and asecond position in which the needle retainer releases the needleallowing the biasing element to displace the needle into the retractedposition. The guidewire engages the needle retainer to impede the needleretainer from displacing into the released position. After the guidewireis threaded into the patient, the needle retainer is displaced into thereleased position, and the biasing element propels the needle rearwardlyinto the housing.

The present invention also provides a method for inserting a medicalapparatus carried by a needle, such as an intravenous catheter orguidewire. The method includes the step of providing an insertion devicehaving a housing, a needle and a needle retainer for releasablyretaining the needle so that the needle projects forwardly from thehousing. The medical apparatus is inserted into the patient via theneedle. The operator selectively manually engages the needle retainer toimpede retraction of the needle. The operator then releases theselective manual engagement with the needle retainer to release theneedle. The needle is then retracted into the housing.

DESCRIPTION OF DRAWINGS

The foregoing summary as well as the following detailed description ofthe preferred embodiments of the present invention will be betterunderstood when read in conjunction with the appended drawings, inwhich:

FIG. 1 is a perspective view of a catheter insertion device having aretractable needle;

FIG. 2 is a cross-sectional view of the device shown in FIG. 1;

FIG. 3 is a cross-sectional view of the device shown in FIG. 2,illustrating the device with the catheter removed prior to retraction ofthe needle;

FIG. 4 is a cross-sectional view of the device shown in FIG. 2,illustrating the device after retraction of the needle;

FIG. 5 is a cross-sectional view of an alternate embodiment of acatheter insertion device having a retractable needle;

FIG. 6 is a cross-sectional view of the device shown in FIG. 5,illustrating the device with the catheter removed prior to retraction ofthe needle;

FIG. 7 is a cross-sectional view of the device shown in FIG. 5,illustrating the device after retraction of the needle;

FIG. 8 is a side elevational view of a retractable needle device forintroducing a guide wire into a patient;

FIG. 9 is an enlarged fragmentary sectional view of the guide wireintroduction device illustrated in FIG. 8;

FIG. 10 is a side view of the guide wire introduction device illustratedin FIG. 8, illustrating is the needle in a retracted position;

FIG. 11 is a side elevational view of a second embodiment of aretractable needle device for introducing a guide wire into a patient;

FIG. 12 is a side view of the guide wire introduction device illustratedin FIG. 11, illustrating the needle in a retracted position;

FIG. 13 is a side elevational view of a catheter insertion device with aretractable needle according to the present invention;

FIG. 14 is a bottom plan view of the catheter insertion deviceillustrated in FIG. 13;

FIG. 15 is a sectional view of the catheter insertion device illustratedin FIG. 13;

FIG. 16 is a bottom plan view of a needle retainer of the catheterinsertion device illustrated in FIG. 13;

FIG. 17 is a side elevational view of the catheter insertion deviceillustrated in FIG. 16;

FIG. 18 is a side elevational view partially in section of an alternateembodiment of a catheter insertion device with a retractable needleaccording to the present invention;

FIG. 19 is an enlarged fragmentary view of the catheter insertion deviceillustrated in FIG. 18, illustrating a locking button in a lockedposition;

FIG. 20 is a side elevational view partially in section of the catheterinsertion device illustrated in FIG. 18, showing the needle in aretracted position;

FIG. 21 is an enlarged fragmentary view of the catheter insertion deviceillustrated in FIG. 20, illustrating the locking button in an unlockedposition;

FIG. 22 is a sectional view of a second alternate embodiment of acatheter insertion device with a retractable needle according to thepresent invention;

FIG. 23 is a sectional view of the catheter insertion device illustratedin FIG. 22, illustrating the needle in a retracted position;

FIG. 24 is an enlarged fragmentary sectional view of the catheterinsertion device illustrated in FIG. 23; and

FIG. 25 is an enlarged fragmentary sectional view of the catheterinsertion device illustrated in FIG. 23.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the FIGS. 1-4 in general and to FIG. 1 specifically, adevice for inserting an over-the needle catheter 70 into a patient isdesignated generally 10. The device 10 includes a retractable needle 30for piercing the skin of the patient to insert the catheter 70. Afterthe catheter 70 is inserted into the patient, the needle 30automatically retracts into the device 10 so that the sharpened tip ofthe contaminated needle is enclosed within the device to preventinadvertent needle sticks.

Referring to FIGS. 2-4, the device includes a generally cylindricalhousing 20, the needle 30, a spring 60 biasing the needle rearwardly,and a needle retainer 40 releasably retaining the needle against thebias of the spring. The needle is operable between two positions, aprojecting position and a retracted position. In the projectingposition, the needle 30 projects forwardly from the forward end of thehousing 20. In the retracted position, the needle is retracted into thehousing so that the sharpened tip is enclosed within the housing toprevent inadvertent contact with the sharpened tip. When the needle isin the projecting position, as shown in FIG. 2, the spring biases theneedle rearwardly toward the retracted position. The needle retainerreleasably retains the needle in the projecting position, against thebias of the spring. The needle retainer cooperates with the catheter 70,so that when the catheter is removed from the device the needle retainerautomatically releases the needle and the needle retracts into thehousing, as shown in FIG. 4.

Referring now to FIG. 2, the elements of the device will be described ingreater detail. The housing is generally cylindrical and the forward endof the housing 20 has a reduced diameter tapered nose 22. The catheter70 is mounted on the nose 22. Accordingly, the nose 22 is tapered tocooperate with the internal taper of the hub 72 of the catheter 70.

The catheter 70 includes a generally conical hub 72 and a flexiblecannula 74 fixedly connected to the catheter hub. The catheter 70 ismounted on the nose 22 of the housing so that the cannula 74 sheaths theforward end of the needle. However, the sharpened tip of the needleprojects forwardly from the cannula so that the sharpened tip is exposedprior to use.

When the catheter 70 is mounted on the nose 22, the catheter hub 72engages the needle retainer 40. The needle retainer 40 is an elongatedarm fixedly connected with the needle 30. The arm projects forwardlythrough an opening in the forward end of the housing, adjacent the tip.The forward portion of the arm 40 forms a follower portion 46. Thefollower portion projects forwardly from the housing, through theopening in the housing adjacent the nose 22 and engages the catheter hub72.

The needle retainer 40 includes a ridge 45 that protrudes radiallyoutwardly, rearwardly of the follower portion 46. The ridge 45 engages alip 24 formed by the opening through which the arm 40 projects adjacentthe nose. The ridge 45 operates as a latch to retain the needle retainerand the attached needle against the bias of the spring.

When the catheter 70 is mounted on the nose 22, the catheter hub 72engages the follower portion 46 of the needle retainer 40 so that theridge 45 is wedged into engagement with the lip 24. In this way, whenthe catheter is mounted on the device, the needle 30 is maintained inthe projecting position against the bias of the needle. Removing thecatheter 70 allows the needle retainer to deflect radially inwardlydisengaging the ridge from the lip. In the present instance, therearward bias of the spring radially deflects the needle retainer whenthe catheter is removed.

The needle retainer arm is formed of a flexible plastic so that the armis resiliently deformable. In its relaxed state, the needle retainer arm40 is disposed into engagement with the lip 24 of the forward opening.Preferably, the lip 24 is tapered rearwardly and the ridge 45 on theneedle retainer 40 forms a mating tapered surface. These mating surfacescan be seen most clearly in FIGS. 3 and 4. Configured in this way, therearward axial biasing force of the spring acts upon the arm in the formof a radial force component and an axial force component. The radialforce component urges the needle retainer arm 40 inwardly so that theridge 45 rides up and over the lip 24 until the ridge is out ofengagement with the lip. The spring 60 then propels the needle retainerand the attached needle rearwardly into the housing so that thesharpened tip of the needle is enclosed within the housing.

The device 10 further includes a fluid reservoir 50 attached to therearward end of the needle, enclosing the rearward end of the needle.The fluid reservoir 50 is in fluid communication with the needle 30 andoperates as a flashback chamber. Accordingly, when the needle isinserted into a patient's vein, blood flows through the needle into theflashback chamber. The rearward end of the flashback chamber 50 issealed by a porous hydrophobic vent plug 52. Air passes though the ventplug to allow air to pass out of the flashback chamber when the bloodenters the flashback chamber. However, the vent plug 52 is not permeableto blood to prevent blood from leaking out of the flashback chamber. Thehousing and the flashback chamber are formed of translucent plastic sothat the blood in the flashback chamber serves as a visible indicatorthat the needle is properly inserted into the patient's vein.

In the present instance, the flashback chamber 50 and the needleretainer 40 are integrally formed as a unitary structure. The twoelements are fixedly attached to the needle by an adhesive such as UVcurable epoxy. The spring is disposed within the housing, circumscribingthe needle. The forward end of the spring bears against the forward endof the housing, the other end of the spring bears against the integralneedle retainer and flashback chamber.

In the present instance, the housing 20 is shorter than the combinedlength of the needle 30 and the flashback chamber 50. Accordingly, therearward end of the housing 20 is generally open, allowing the flashbackchamber to project rearwardly out of the housing when the needle isretracted, as shown in FIG. 4. The device also includes a locking orlimiting feature to ensure that the needle is not propelled rearwardlyout of the housing. Preferably, an aperture 26 sized to receive theforward portion 46 of the needle retainer arm 40 is formed in the sideof the housing operates as the rearward lock. The resilience of theneedle retainer biases the needle retainer radially outwardly. When theneedle is propelled rearwardly, the forward end of the needle retainer46 engages the aperture 26 so that the ridge 45 engages the rearwardedge of the aperture, retaining the needle against continued rearwarddisplacement. In addition, the forward end of the needle retainer 40engages the forward edge of the aperture 26 to retain the needle againstforward displacement, so that the needle cannot be re-extended after itis retracted.

When the catheter 70 is removed from the device and inserted into apatient, blood from the patient may flow out the rearward end of thecatheter. Typically, once the catheter is attached to a fluid reservoir,such as an IV bag, the fluid pressure from fluid in the IV bag issufficient to prevent or limit the flow of blood from the patientthrough the catheter. However, until the IV bag is connected to thecatheter, blood may leak out the catheter. Therefore, it is desirable toplug the catheter to prevent blood leakage after the catheter isinserted into a patient.

Accordingly, preferably, the nose 22 forms a fluid-tight seal with theinterior of the catheter hub 72 when the catheter is mounted on thenose. In this way, after the catheter is removed from the housing andthe needle is retracted, the nose can be inserted into the catheter toplug the catheter. Further, referring to FIG. 3, preferably the noseextends forward of the follower portion 46 of the needle retainer 40 sothat the nose 22 substantially plugs the catheter immediately after theneedle is retracted. In addition, since the nose 22 projects forward ofthe follower portion 46, the needle is never exposed during and afterretraction.

Configured as described above, the device operates as follows. Prior touse, the needle 30 is disposed in the projecting position so that thesharpened tip of the needle is exposed. The sharpened tip of the needleis inserted into a vein of a patient. Blood flowing into the flashbackchamber 50 indicates to the medical professional that the needle isinserted into a vein. The catheter 70 is then threaded into thepatient's vein by advancing the catheter to remove the catheter from thedevice 10. For this purpose, preferably, the catheter hub 72 includes aprotrusion 73 that the medical professional can push forward with one ofthe fingers of the hand holding the device. When the catheter isadvanced forward of the follower portion 46 of the needle retainer 40,the needle retainer 40 deflects inwardly so that the needle is released.The spring 60 then propels the needle 30, the needle retainer 40 and theflashback chamber 50 rearwardly so that the sharpened tip of the needleis enclosed within the housing 20. If the medical profession desires todo so, the nose 22 can then be inserted into the catheter to replug thecatheter to prevent blood leakage.

Referring now, to FIGS. 5-7 an alternative embodiment, which is thepreferred embodiment is illustrated. Elements in the second embodimentthat are similar to elements of the first embodiment illustrated inFIGS. 1-4 and described above are designated with like referencenumbers, with the addition of 100s thereto.

The second embodiment is designated generally 110. The device 110includes a housing 120, a retractable needle 130, a spring 160 biasingthe needle rearwardly, and a needle retainer 140 releasably retainingthe needle against the bias of the spring. An over-the-needle catheter170 is mounted on the forward end of the device 110. The needle retainer140 cooperates with the catheter so that upon removing the catheter fromthe device 110, the needle is released, and the spring propels theneedle rearwardly into the housing 120.

The needle retainer 140 is configured similarly to the needle retainer40 described in connection with the first embodiment. The needleretainer comprises an elongated resiliently flexible arm fixedlyconnected with the needle 30. The forward end of the needle retainerprojects through an opening at the forward end of the housing adjacentthe tip 122. The forward portion 146 of the needle retainer engages theside of the catheter hub 172. Similar to the first embodiment, thecatheter hub 172 wedges the needle retainer arm radially outwardly sothat a ridge 145 on the arm engages a lip 124 formed by the opening atthe forward end of the housing. Accordingly, when the catheter 170 isremoved from the device 110, the needle retainer 140 deflects inwardlyto release the needle 30. The spring then propels the needle rearwardlyinto the housing 120. As shown in FIG. 7, the housing is elongated sothat the entire length of the needle and the flashback chamber isenclosed within the housing in the retracted position.

In this way, as with the first embodiment, the needle automaticallyretracts after use so that the medical professional need not perform anyadditional steps to ensure that the contaminated needle is safelyenclosed. The step of inserting the catheter 170 into the patient issufficient to effectuate retraction. However, as discussed furtherbelow, the medical professional may delay retraction if desired.

It may be desirable to allow the medical professional to delayretraction after the catheter is inserted into the patient. Therefore,the device 110 includes a window 121 in the side of the housing 120. Theneedle retainer 140 is disposed adjacent the window allowing the medicalprofessional to manually engage the needle retainer. If the medicalprofessional desires to control retraction, the medical professional canapply pressure to deflect the needle retainer radially inwardly so thatthe retainer abuts an interior wall 125. In this way, the needleretainer is pinched between the grip of the medical professional and theinterior wall to prevent the needle from retracting into the housing.Once the medical professional releases the needle retainer, the needleretracts into the housing.

Preferably, the window 121 is located so that the medical professionalengages the needle retainer when grasping the device 110 for use. Forthis reason, preferably, a gripping portion is formed at the forward endof the housing. The gripping portion is formed by a pair of opposingconcavely curved surfaces along the sides of the housing. The window 121is formed in one of the opposing curved surfaces of the grippingportion.

The device operates as follows. Prior to use, the needle projectsforwardly from the housing as shown in FIG. 5. The medical professionalgrasps the gripping portion of the housing to hold the device 110. Indoing so, the medical professional engages the needle retainer throughthe window 121. The needle 130 is inserted intravenously into a patient.Once blood flow is detected in the flashback chamber 150, the catheteris axially advanced to insert the catheter into the patient. Once thecatheter is axially advanced forward of the needle retainer, the needleis freed to retract except for the force being applied to the needleretainer by the medical professional. If the medical professional doesnot want to delay retraction the medical professional can release thefinger pressure on the needle retainer so that the bias of the springovercomes the finger pressure. Alternatively, the medical professionalcan delay retraction by maintaining his or her grip with sufficientforce to overcome the bias of the spring 160. Once the medicalprofessional releases the device, the needle automatically retracts intothe housing so that the sharpened tip of the housing is enclosed. Inthis way, the needle automatically retracts after the device is used,and without any additional step, such as depressing a button. At thesame time, if the medical professional desires to control retraction bydelaying retraction, he or she may do so, without performing anyadditional steps. The natural steps of using the device allow suchcontrol. However, even if the medical professional desires to delay theretraction, the needle will eventually automatically retract without anyfurther operation once the medical professional releases his or her gripon the device.

The device 110 also includes an adjustable nose piece 22. In the firstembodiment, the nose 22 is integrally formed with the housing. In thesecond embodiment, the nose is a separate piece that is inserted into asocket at the forward end of the housing that is formed to receive thenose piece. The nose piece 122 may be axially adjusted relative to thehousing 120. By adjusting the axial position of the nose piece, thelength of the exposed sharpened needle tip projecting from the cathetercannula can be varied.

Referring now to FIGS. 8-10 generally and to FIG. 8 specifically, adevice for introducing a guide wire 270 into a patient is designatedgenerally 210. The device includes a needle 240 for piercing a vein ofthe patient. The guide wire is inserted into the patient's vein throughthe needle. After the guide wire is inserted into the patient, theinsertion needle automatically retracts to that the contaminated needleis beyond the reach of the medical professional using the device. Inaddition, the medical professional using the device can controlretraction of the device to delay retraction if desired. However, evenif retraction is delayed, retraction occurs automatically once themedical professional puts the device down.

As shown in FIG. 8, the device includes a housing 220 having a reduceddiameter tip 224. The needle 240 projects forwardly through an openingin the tip 224. The rearward end of the housing 220 is generally closed,having a reduced diameter opening through which the guide wire 270enters the interior of the housing. A rubber seal 280 is disposed in therearward end of the housing. The guide wire 270 extends through a holein the seal, forming a fluid-tight seal with the seal 280. In addition,seal 80 frictionally engages the guide wire to frictionally connect theguide wire to the housing 220.

Rearward of the tip 224, the housing has a gripping area 222 formed of aplurality of raised ridges. During ordinary operation, the user graspsthe gripping area to hold the device during insertion of the guide wire.

A spring 260 circumscribes the needle, biasing the needle 240 rearwardlytoward a retracted position. A needle retainer 230 releasably retainsthe needle in the projecting position, in which the needle projectsforwardly from the housing, as shown in FIG. 8. The needle retainer 230comprises an elongated arm 232 that is pivotally connected to thehousing 220 by a pivot pin 233 that forms the pivot axis for the motionof the needle retainer. A latch 235 is integrally formed on the arm 232on the end of the arm remote from the pivot pin 233. The latch 235projects into the interior of the housing.

Referring now to FIG. 9, the latch 235 engages a flash back chamber 250that is affixed to the rearward end of the needle 240. The flashbackchamber is a generally cylindrical hollow chamber. The rearward end ofthe needle has a side port 242 so that when the needle pierces thepatient's vein, blood flows through the side port and into the flashbackchamber to indicate to the medical professional that the vein has beenpierced. Prior to advancing the guide wire 270, the guide wire projectsinto the needle 240 so that the forward end of the guide wire isrearward of the side port 242 in the needle. In this way, the guide wireseals the rearward end of the needle to prevent blood from leaking outthe rearward end of the flashback chamber. At the same time, the guidewire does not block the side port so that blood can flow through theneedle and into the flashback chamber.

The forward end of the flashback chamber 250 is sealed by a porous ventthat is air permeable, but does not allow passage of blood from theflashback chamber. The rearward end of the flashback chamber isgenerally closed, having a small opening for receiving the guide wire270. The guide wire passes through the rearward opening and into theneedle. In this way, the guide wire seals the opening in the rear of theflashback chamber to prevent blood from leaking out of the flashbackchamber.

As described above, the needle retainer pivots between a latchedposition in which the needle retainer retains the needle in theprojecting position against the rearward bias of the spring, and anunlatched position in which the needle retainer releases the needle,allowing the spring to propel the needle rearwardly into the housing sothat the sharpened end of the needle is enclosed. The needle retainer230 automatically pivots from the latched position to the unlatchedposition after the guide wire 270 is inserted into the patient. Theguide wire 270 prevents the needle retainer from pivoting into theunlatched position until the guide wire is inserted into the patient.

Specifically, a passageway 236 extends through the latch 235 forreceiving the guide wire. The guide wire 270 projects through the latchpassageway 236 and into the flashback chamber as shown in FIG. 10. Whilethe guide wire resides within the latch passageway, the latch isprevented from pivoting into the unlatched position. When the rearwardend of the guide wire 270 is displaced forwardly of the passageway sothat the guide wire is removed from the passageway, the guide wire nolonger retains the latch against being displaced radially outwardly. Therearward bias of the spring 260 urges the needle and attached flashbackchamber rearwardly. This in turn urges the latch radially outwardly, sothat the arm 232 pivots radially outwardly away from the needle. Thespring then propels the needle into the housing 220 as shown in FIG. 10.

As mentioned previously, the medical professional operating the device210, can optionally intervene to delay retraction. Specifically, asshown in FIG. 8, in the latched position the needle retainer 230 resideswithin a slot in the gripping portion. In this way, when the medicalprofessional grasps the gripping portion 222, the medical professionalalso grasps the arm 232 of the needle retainer. As long as the medicalprofessional grasps the needle retainer, the needle retainer will notpivot into the unlatched position. In this way, the medical professionalcan delay retraction after the guide wire is inserted into the patient.However, as soon as the medical professional releases the needleretainer 230, the needle retainer will pivot into the unlatched positionand the spring will propel the needle into the retracted position.

Configured in this way, the device operates as follows. The needle 240is inserted into a patient. Blood flowing into the flashback chamberprovides a visual indication that the needle has been inserted into avein. The medical professional then advances the guide wire 270 throughthe needle to insert the guide wire into the patient's vein. As theguide wire is advanced, the guide wire passes through the passage 236that extends through the latch 235. Once the guide wire 270 is advancedforward of the latch, the needle retainer pivots into the unlatchedposition and the spring propels the needle rearwardly into the housing220. If the medical professional desires to delay retraction, themedical professional grasps the needle retainer prior to advancing theguide wire forwardly of the latch. The guide wire is then advancedforwardly of the latch while the medical professional continues to graspthe needle retainer. When the medical professional desires to retractthe needle, the medical professional needle simply releases his or hergrip on the needle retainer. The spring then automatically propels theneedle rearwardly into the retracted position.

Referring now to FIGS. 11-12, a second embodiment of a device forintroducing a guidewire 370 into a patient is designated generally 310.The device includes a needle 340 for piercing a vein of the patient. Theguidewire 370 is inserted into the patient's vein through the needle.After the guidewire is inserted into the patient, the insertion needleautomatically retracts into the housing 320 so that the contaminatedneedle is beyond the reach of the medical professional using the device.In addition, the medical professional using the device can controlretraction of the device to delay retraction if desired. However, evenif retraction is delayed, retraction occurs automatically once themedical professional puts the device down.

The guidewire 370 is preferably a substantially inextensiblesemi-flexible wire. The forward end of the guidewire is rounded, andpreferably the wire is solid. The wire is sized so that the diameter ofthe wire is slightly smaller than the interior bore of the needle 340 sothat the wire is slidable within the needle.

The device includes a hollow housing or barrel 320. The needle 340projects forwardly through an opening in the forward end of the housing340. The rearward end of the housing 320 is generally closed, having areduced diameter opening through which the guidewire 370 enters theinterior of the housing. A rubber seal 380 is disposed in the rear ofthe housing. The guidewire 370 extends through a hole in the seal 380,forming a fluid-tight seal with the rubber seal. In addition, the seal380 frictionally engages the guidewire to frictionally connect theguidewire to the housing 320.

A spring 360 circumscribes the needle, biasing the needle 340 rearwardlytoward a retracted position, shown in FIG. 12. A needle retainer 30releasably retains the needle in the projecting position, in which theneedle projects forwardly from the housing, as shown in FIG. 11. Theneedle retainer 330 is an elongated arm integrally formed from thehousing, so that the arm 330 and the housing 320 are formed of aone-piece construction. The arm 330 is formed so that the arm is biasedradially outwardly toward the position illustrated in FIG. 12.

As shown in FIG. 11, prior to use the arm 330 projects into the interiorof the housing 320. The forward end of the arm 330 forms a latch 335that engages a flashback chamber 350 fixed to the rearward end of theneedle 340. The flashback chamber 350 is a generally cylindrical hollowchamber. The rearward end of the needle has a side port 342 so that whenthe needle pierces the patient's vein, blood flows through the side portand into the flashback chamber to indicate to the medical professionalthat the vein has been pierced. Prior to advancing the guidewire 370,the guidewire projects into the needle 340 so that the forward end ofthe guidewire is rearward of the side port 342 in the needle. In thisway, the guidewire seals the rearward end of the needle to prevent bloodfrom leaking out the rearward end of the flashback chamber. At the sametime, the guidewire does not block the side port so that blood can flowthrough the needle and into the flashback chamber.

The forward end of the flashback chamber 350 is sealed by a porous eventthat is here permeable, but does not allow passage of blood from theflashback chamber. The rearward end of the flashback chamber isgenerally closed, having a small opening for receiving the guidewire370. The guidewire passes through the rearward opening and into theneedle. In this way, the guidewire seals the opening in the rear of theflashback chamber to prevent blood from leaking out of the flashbackchamber.

As described above, the needle retainer pivots between a latchedposition in which the needle retainer retains the needle in theprojecting position against the rearward bias of the spring 360, and anunlatched position in which the needle retainer releases the needle,allowing the spring to propel the needle rearwardly into the housing sothat the sharpened end of the needle is enclosed. The needle retainer330 automatically pivots from the latched position to the unlatchedposition after the guidewire 370 is threaded into the patient. Theguidewire 370 prevent the needle retainer from pivoting into theunlatched position until the guidewire is threaded into the patient.

Specifically, the arm 330 includes a forward wire passageway 332 and arearward wire passageway 334 for receiving the guidewire 370. Thepassageways 332,334 are located and oriented so that when the arm 330 isdisposed in the latched position, illustrated in FIG. 11, thepassageways 332,334 are substantially co-axial with the needle 340. Inthis way, the guidewire 370 engages the needle retainer arm 330 toreleasably retain the arm in the latched position, thereby releasablyretaining the needle 340 in the projecting position against the bias ofthe spring 360. While the guidewire 370 resides within one of the latchpassageways 332, 334, the arm is prevented from pivoting into theunlatched position. When the rearward end of the guidewire 370 isdisplaced forwardly of the forward wire passageway 332 so that theguidewire is removed from the passageway, the guidewire no longerretains the arm against being displaced radially outwardly. The rearwardbias of the spring 60 urges the needle 340 and attached flashbackchamber 350 rearwardly. This, along with the radial bias of the arm 330urges the arm radially outwardly, so that the arm pivots radiallyoutwardly away from the needle. The spring then propels the needle intothe housing 320 as shown in FIG. 12.

As shown in FIG. 11, preferably the arm 330 is bent to form a trough ordepression. Preferably, the top surface of the trough is verticallyspaced below the center line or axis of the needle 340. As shown in FIG.11, a portion of the guidewire 370 between the wire passageways 332,334is external of the housing 322 and exposed for manual manipulation bythe medical professional. In this way, the medical professional can bothhold the device and feed the guidewire 370 into the patient with onehand. Specifically, while holding the device 310 with one hand, themedical professional can engage the exposed portion of the wire betweenthe passageways 332, 334 and displace the guidewire forwardly to threadthe guidewire through the needle 340 and into the patient.

Referring now to FIGS. 13-17 in general and to FIG. 13 specifically,there is shown a catheter insertion device 410 for inserting a catheter450 into a patient. The device 410 has a needle 420 to guide thecatheter 450 into a vessel of the patient. The insertion device 410 isadapted to automatically retract the needle 420 inside the insertiondevice 410 when the operator removes the catheter 450 from the device.In addition, the device is configured to allow the operator to delay theretraction. These features allow the operator to control retraction,while ensuring that the needle automatically retracts after use torender the needle non-reusable and safely disposable.

The catheter insertion device 410 includes a generally cylindricalhollow barrel or housing 430 having a reduced diameter forward tipportion 434. The needle 420 is releasably retained so that the forwardend of the needle projects forwardly through a hole in the barrel tip434. The needle is operable between an extended position and a retractedposition. In the retracted position, the needle is enclosed within thehousing.

The catheter 450 is initially mounted on the forward end of the catheterinsertion device 410 with the needle 420 projecting from the front ofthe device through the catheter. The catheter 450 comprises a cannula452 and a hub 454. The cannula 452 sheaths or receives the front portionof needle 420, so that the sharpened point of the needle extendsslightly beyond the open end of the cannula.

The catheter 450 includes a flexible, elongated cannula 452 attached tothe catheter hub 454. The cannula 452 telescopingly engages the needleso that the cannula sheaths the needle, with the sharpened tip of theneedle 422 projecting beyond the forward end of the cannula. Therearward edge of the sharpened tip 422 is referred to as the heel of theneedle bevel. The length of the needle between the heel of the needlebevel and the forward end of the cannula is referred to as the lielength. Preferably, the lie length is adjustable.

In the present instance, the lie length is adjustable by maintaining theextended position of the needle constant, and adjusting the position ofthe catheter 450 when the catheter is mounted on the barrel prior touse. The tip of the barrel 420 is adjustable to provide for adjustmentof the catheter.

Referring now to FIG. 15, the barrel 420 includes a displaceable tip434. In the present instance, the tip 434 is a separate component thatis inserted into an opening at the forward end of the barrel 430. Thetip 434 includes an external circumferential flange 439 against whichthe rearward edge 455 of the catheter hub 454 seats. Therefore, varyingthe axial position of the tip 434 adjusts the axial position of theflange 439 thereby adjusting the lie length.

The tip 434 includes a generally cylindrical rearward portion having anexternal diameter that is slightly less than the internal diameter ofthe forward portion of the barrel 430. A plurality of barbs 438 projectfrom the external surface of rearward end of the tip 434. The barbs 438engage the internal surface of the barrel 430 to connect the tip 434 tothe barrel. The axial position of the flange 439 is determined by thedistance that the rearward end of the tip is inserted into barrel 430.By adjusting the amount the tip is inserted, the axial position of theflange 439 is adjusted, thereby adjusting the lie length.

As shown in FIG. 15, a generally cylindrical chamber 470 is attached tothe rearward end of the needle. The chamber 470 forms a flashbackchamber. The flashback chamber 470 is attached to the rearward end ofthe needle 420 so that the flashback chamber encloses the rearward endof the needle 420. The rearward end of the flashback chamber is closedby a porous vent plug 472. The vent plug 472 allows the passage of airout of the chamber 470, while preventing blood from escaping from theflashback chamber 470.

The needle 420 is biased rearwardly toward its retracted position by abiasing element 460. In the present instance, the biasing element is acoil spring 460 that surrounds the needle. The forward end of the spring460 bears against an internal shoulder formed in the tip 434. Therearward end of the spring bears against the flashback chamber 470,biasing the flashback chamber and the attached needle rearwardly.Alternatively, the spring 60 may be connected to the needle by anadhesive, such as epoxy. The needle 420 and flashback chamber 470 arereleasably retained against the bias of the spring 460 by a needleretainer or lever arm 440 that is pivotally connected to the housing430.

The needle retainer 440 has a forward portion 444 and a rearward portion448. In the present instance, the forward portion 444 extends in theforward direction from a pivot 442, and the rearward portion 48 extendsrearwardly from the pivot 442. The interior surface of the forwardportion 444 of the retainer 440 abuts with the hub 454 of the catheter450 when the catheter is mounted on the insertion device 410.Preferably, the forward portion 444 of the retainer 440 abuts or engagesthe external surface of the catheter hub 454. Alternatively, the forwardportion may engage the internal surface of the catheter hub 454. Therearward portion 448 of the needle retainer 440 is located rearwardlyfrom the pivot point and catheter 450, when the catheter is mounted onthe insertion device.

The rearward portion 448 of the needle retainer 440 comprises a releaselever having a latch 446 formed thereon. The lever is pivotable betweena locked position and an unlocked position. In the locked position, therelease lever extends generally parallel to the longitudinal axis of thedevice 410. The latch 446 on the end of the release lever passes throughan opening 432 in the side of the barrel 430, so that the rear end ofthe flashback chamber 470 abuts the latch to retain the needle in itsextended position.

It is desirable to align the sharpened tip 422 of the needle 420 so thatthe bevel of the sharpened tip is circumferentially located relative tothe barrel 430, as illustrated in FIG. 13. Specifically, preferably, thesharpened tip is circumferentially located so that the forward-mostpoint of the sharpened tip is vertically positioned below the heel ofthe tip bevel. In the present instance, the flashback chamber 470 isconfigured to cooperate with needle retainer to facilitate aligning thebevel of the needle, as described below.

The flashback chamber 470 is generally cylindrical, and includes a flatsurface extending along the length of the flashback chamber. The desiredcircumferential orientation of the needle bevel is located relative tothe flat on the flashback chamber when the flashback chamber isconnected to the needle. Referring to FIG. 15, the rearward portion 448of the needle retainer includes a generally planar surface or ledge 449that cooperates with the flashback chamber 470 to circumferentiallyalign the needle 420 relative to the barrel 430. As shown in FIG. 15,when the needle retainer 440 is disposed in the latched position, theflat on the flashback chamber 470 is aligned with and engages the ledge449 of the needle retainer. In this way, the flashback chamber 470 andthe attached needle 420 are circumferentially located relative to theneedle retainer, and in turn to the barrel 430.

The engagement between the forward portion 444 of the needle retainerlever and the catheter hub 454 prevents the lever from pivoting to itsunlocked position when the catheter is mounted on the insertion device.The rear portion 48 of the retainer 440 is preferably biased to pivotaway from the side of the housing 430. In the present instance, the faceof the latch 446 that engages the flashback chamber 470 is angled sothat a portion of the rearward bias of spring 460 is transferred to thelever biasing the lever radially outwardly. After the catheter 450 isremoved past the end of the lever, the retainer is free to pivot intoits unlocked position, thus moving the latch 446 out of engagement withthe rear end of the needle 420. The spring 460 then propels the needlerearwardly into the housing 430.

The operator can control retraction of the needle, if desired, asfollows. The needle retainer 440 includes a rib 445 that is transversethe longitudinal axis of the needle retainer lever. As shown in FIGS. 13and 14, the barrel 430 includes a gripping portion comprised of aplurality of parallel spaced apart ribs 431. The needle retainer rib 445is generally parallel to the gripping ribs 431 so that the needleretainer rib 445 forms part of the gripping portion. In this way, if theoperator desires to control retraction of the needle, the operatorgrasps the rib 445 of the needle retainer when grasping the grippingportion of the device 410.

By grasping the needle retainer rib 445, the operator impedes pivotingof the needle retainer 440 from the locked position to the unlockedposition. After the operator inserts the catheter 450 into the patient,the forward portion 444 of the needle retainer is disengaged from thecatheter, thereby allowing the needle retainer to pivot toward theunlocked position. However, the operator's grasp of the needle retainerrib 445 operates as an override preventing the needle retainer frompivoting into the unlocked position. The operator can control retractionby maintaining an inward force on the needle retainer rib 445 untilretraction is desired. Once the operator releases the needle retain rib445 after the catheter 450 has been disengaged from the needle retainer440, the needle retainer is free to pivot into the unlocked position sothat the spring 460 propels the needle 420 rearwardly into the barrel430. In this way, the device prevents retraction from occurring untilafter the catheter 450 is disengaged from the housing of the insertiondevice. In addition, the device allows the operator to control thetiming of retraction, while ensuring that retraction occurs after use ofthe device.

The catheter insertion device is initially provided in the configurationshown in FIG. 13. The operator of the catheter insertion device 410first uses the needle point 422 to pierce a blood vessel of the patient.When the needle point 422 pierces the patient's blood vessel, bloodflows through the needle 420 and collects in the transparent flashbackchamber 470. The appearance of blood in the flashback chamber 470 servesas a visible indication to the operator that a blood vessel has beenappropriately pierced, and that the catheter 450 is properly positioned.The operator then slides the catheter hub 454 off of the forward end ofthe device 410, in the direction of the pointed end 422 of the needle420, to insert the catheter lumen 452 into the patient's blood vessel.This motion of removing the catheter hub 454 from the device causes theretainer 440 to automatically pivot out of contact with the end of theneedle when the rim 455 of the catheter hub passes the end of lever 444.However, the operator can temporarily override the automatic retractionby grasping the needle retainer rib 445 prior to removing the catheterhub. Once the operator releases the needle retainer rib 445, the needleretainer pivots out of engagement with the needle 420. The needle isthereby released and withdrawn into the barrel 430 of the catheterinsertion device 410 under the bias of spring 460. The operator need notperform any additional action to effectuate retraction of the needleother than that required by a normal catheter insertion procedure. Atthe same time, the operator can intervene to delay retraction, ifdesired.

Referring to FIG. 15, the tip 434 further includes a constricted portion435 having an internal diameter slightly larger than the externaldiameter of the needle 420. The close fit between the constrictedportion 435 and the needle limits leakage of blood into the barrel 430during a replugging step, as described further below. In addition, anexternal circumferential rib 437 protrudes radially from the front endof the tip 434. The rib 437 cooperates with the internal cavity of thecatheter hub 454 to provide a fluid-tight seal. The internal cavity istapered, having a major diameter that is greater than the diameter ofthe rib 437 on the tip 434. Preferably, a substantially cylindrical zerodraft zone is formed at the forward-most portion of the internal cavity.The zero draft zone has an internal diameter that is similar to theexternal diameter of the rib 437 on the tip 434. In this way, when thecatheter 450 is mounted on the barrel 430, the rib 437 engages the zerodraft zone to form a fluid-tight seal.

After the catheter has been inserted into the patient and the needle 420has been retracted, the tip 434 of the device can be inserted into thecatheter 450 to replug the catheter to prevent blood from leaking out ofthe catheter. For this reason, the catheter 450 and/or the forward endof the needle retainer 440 are configured to facilitate pivoting of theneedle retainer so that the forward end of the needle retainer does notinterfere with replugging of the catheter. Specifically, the forwardedge of the needle retainer is rounded so that the forward portion 444of the needle retainer 440 pivots downwardly from the perspective ofFIGS. 13 and 15 when the needle retainer engages the rim 455 of thecatheter 450. Alternatively, the rim 455 can be rounded or tapered tofacilitate pivoting of the needle retainer 440 upon forward axialdisplacement of the tip 434 relative to the catheter 450 after thecatheter has been removed from the device a sufficient amount todisengage the needle retainer from the needle 420.

The catheter 450 is replugged after retraction by inserting the tip 434of the barrel 430 into the catheter cavity so that the circumferentialrib 437 engages the zero draft zone. The rib 437 and the zero draft zonecooperate to form a fluid-tight seal so that blood does not leak fromthe catheter around the tip 434. In addition, the retracted needle 420forms a seal with the constricted portion 435 of the tip 434 to reduceor eliminate blood leakage from the catheter 450 into the barrel 430. Inthe retracted position, the latch 446 deflects and/or deforms theneedle.

The tip 434 further includes an external circumferential depression orrecess 436. Initially, the catheter 450 encloses the tip 434 so that theoperator cannot see the recess 436. As the operator removes the catheter450 from the tip 434, the recess 436 is uncovered so that the operatorcan see the recess. After the recess 436 is uncovered, continued removalof the catheter 450 displaces the catheter beyond the forward end of theneedle retainer 440, so that the needle retainer pivots into theunlatched position. In this way, the recess operates as a visualindicator to the operator, providing a visual signal that continuedforward displacement of the catheter will cause needle retraction.Preferably, the recess 436 is textured to enhance the visual distinctionbetween the recess and the rest of the external surface of the tip.Alternatively, a different visual indicator can be provided, such as acircumferential colored line located on the tip 434 axially rearwardlyof the forward end of the needle retainer 440.

Referring now to FIGS. 18-20, there is shown an alternate embodiment ofa catheter insertion device 510. The alternate embodiment shown in FIGS.17-20 incorporates elements that are similar to elements in the firstembodiment described above in connection with FIGS. 13-17. Parts inFIGS. 18-20 that are similar to the parts in FIGS. 13-17 are numbered bythe same number designator with the addition of 50's thereto.

The catheter insertion device 510 includes an insertion needle 520projecting forwardly from a barrel or housing 530. The needle 520 isreleasably retained by a needle retainer 540 comprising a release lever.The needle retainer 540 engages a catheter 550 mounted on the tip 534 ofthe housing 530. In this manner, the catheter 550 impedes pivoting ofthe needle retainer 540 and prevents retraction of the needle 520 whilethe catheter is mounted on the housing 530 of the device 510.

As in the embodiment described above in connection with FIGS. 13-17, thecatheter insertion device 510 in FIG. 18 is also operable toautomatically retract the needle without manual intervention orrequiring a separate step for retraction. The needle retainer 540 isbiased toward an unlatched position, so that when the catheter 550 isremoved from the insertion device 510, the needle retainer 540automatically pivots into its unlatched position, releasing the needle520. The spring 560 then propels the needle 520 rearwardly into thehousing 530, so that the sharpened tip of the needle 520 is safelyenclosed within the housing.

In addition, as in the previous embodiment, the device 510 includes anexposed, manually actuable surface that allows the operator to interveneto delay retraction if desired. Specifically, the device includes acontrol button 580 that engages a pawl 549 connected to the needleretainer 540. The control button 580 operates between a locked positionand an unlocked position. In the locked position the control buttonengages the pawl 549 on the needle retainer 540 preventing the needleretainer from pivoting into the unlatched position to release the needle520. The control button is displaceable toward the unlocked position,which corresponds to the needle retainer 540 being in the unlatchedposition.

The control button 580 and pawl 549 have mating tapered surfaces. Whenthe needle retainer 540 pivots, the mating tapered surfaces of the pawland control button transfers a vertical force to the button, displacingthe control button upwardly into the unlocked position. Accordingly,absent operator intervention, when the catheter 550 is removed from thehousing 530, the needle retainer 540 pivots into the unlatched position,displacing the control button into the unlocked position. The needlethen retracts into the housing.

The operator can intervene to delay retraction by depressing the controlbutton 580 before the catheter is removed. The downward force applied bythe operator on the control button locks the pawl 549 in place,preventing the needle retainer from pivoting. After the catheter isremoved from the housing, the needle retainer retains the needle as longas the operator depresses the control button. As soon as the operatorreleases the control button, the pawl is free to rotate, so that theneedle retainer pivots into the unlatched position and the needleretracts. In this way, retraction of the insertion needle occursautomatically after the device is used, but the operator can delayretraction if desired.

The device 510 also illustrates an alternate arrangement for theflashback chamber 520. The flashback chamber 520 can be configured as inthe previous embodiment in which the flashback chamber 470 encloses therearward open end of the needle 420, and the needle retainer 440 engagesthe flashback chamber. Alternatively, in the present embodiment, therearward end of the needle 520 projects rearwardly from the flashbackchamber 570, and the needle retainer 540 engages the rearward end of theneedle. The rearward end of the needle is plugged to prevent blood fromleaking into the housing. In addition, a side port is formed in the sideof the needle, and the flashback chamber encloses the side port. Bloodfrom the patient flows through the side port and into the flashbackchamber, serving as a visual indicator that the patient's artery hasbeen pierced.

Referring now to FIGS. 22-25, there is shown another alternativeembodiment of a catheter insertion device 610. The device 610incorporates elements that are similar to ones previously described.Such elements are designated with the same number designations with theaddition of 600's thereto.

The catheter insertion device 610 includes an insertion needle 620protecting forwardly from a barrel or housing 630. The needle 620 isreleasably retained by a pivotable needle retainer 640 comprising arelease lever. One end of the needle retainer 640 engages a catheter 650mounted on the tip 634 of the housing 630. In this arrangement, thecatheter 650 impedes the needle retainer 640 from releasing the needle620 while the catheter is mounted on the housing 630 under the retainer640.

As in the embodiment described above in connection with FIGS. 13-21, thecatheter insertion device 610 in FIG. 22 is also operable toautomatically retract the needle without manual intervention orrequiring a separate step for retraction. The needle retainer 640 isbiased toward an unlatched position, so that when the catheter 650 isremoved from the insertion device 610, the needle retainer 640automatically pivots into its unlatched position, releasing the needle620. The spring 660 then propels the needle 620 rearwardly into thehousing 630, so that the sharpened tip of the needle 620 is safelyenclosed within the housing.

In addition, as in the previously described embodiments, the device 610includes an exposed, manually actuable surface that allows the operatorto intervene to delay retraction if desired. Specifically, the housingincludes a gripping portion 691 providing a surface for the operator tograsp the device 610. The needle retainer 640 is located adjacent thegripping portion 631 so that the operator can readily engage the needleretainer to prevent the needle retainer from pivoting into the unlatchedposition.

Referring to FIGS. 22 and 23, the housing 630 includes the grippingportion 631, which is formed of a plurality of parallel spaced apartribs. The ribs form a convex curved surface providing a secure anti-slipsurface. As shown in FIG. 13, the housing may include opposing grippingsurface for gripping the device. In the present instance, the barrelincludes the gripping portion 631 on one side of the housing, and therearward portion 648 of the needle retainer 640 is located on the otherside of the housing, opposing the gripping portion. The exposed surfaceof the rearward portion 648 of the needle retainer 640 is configured andtextured similar to the gripping portion 631. Accordingly, when theoperator grasps the device for use, the operator's normal grip on thedevice operates to depress the rearward portion of the needle retainer.As long as the operator depresses the rearward portion of the needleretainer, the operator prevents the needle retainer from pivotingradially outwardly to release the needle for retraction.

The device 610 also includes a telescoping barrel to reduce the overalllength of the housing prior to use. Alternatively, the device 610 canuse a single piece housing as described above in the foregoing devices410, 510.

The housing 630 of the device 610 comprises two components, an outersleeve 690 and an inner sleeve 695. The inner sleeve 695 telescopeswithin the outer sleeve 690. Prior to use, the inner sleeve 695 isenclosed within the rearward end of the outer sleeve 690. When theneedle 620 is retracted, the flashback chamber 670 and attached needleengages the inner sleeve, displacing the inner sleeve rearwardly as theneedle retracts. In this way, the outer sleeve telescopes outwardlyextending the length of the housing to accommodate the entire length ofthe needle.

The housing includes a forward stop to prevent the inner sleeve 695 frombeing reinserted into the outer sleeve 690. The housing further has arearward stop to prevent the inner sleeve from being displacedrearwardly beyond the rearward edge of the outer sleeve.

A pair of resilient locking tabs 697 formed in the side of the innersleeve 695 cooperates with the rearward edge of the outer sleeve 690 tooperate as the forward stop. The locking tabs 697 are biased radiallyoutwardly. When the inner sleeve 695 is enclosed within the outer sleeve690, the locking tabs 697 engage the inner surface of the outer sleeveso that the locking tabs are substantially flush with the outer surfaceof the inner sleeve. When the inner sleeve is displaced rearwardly sothat the locking tabs are rearward of the outer sleeve, the locking tabsflex radially outwardly as shown in FIGS. 23 and 24. Accordingly,attempts to displace the inner sleeve forwardly after retraction causesthe locking tabs to engage the rear edge of the outer sleeve, therebypreventing forward displacement.

An annular lip 693 on the outer sleeve 690 cooperates with acircumferential flange 696 on the inner sleeve 695 to operate as therearward stop. Referring to FIGS. 23 and 24, the annular lip 693projects radially inwardly from the rearward edge of the outer sleeve690.

The circumferential flange 696 projects radially outwardly from theforward edge of the inner sleeve 695. When the inner sleeve is displacedrearwardly, the circumferential flange 696 engages the annular lip 693impeding further rearward displacement of the inner sleeve.

The terms and expressions which have been employed are used as terms ofdescription and not of limitation. There is no intention in the use ofsuch terms and expressions of excluding any equivalents of the featuresshown and described or portions thereof. It is recognized, however, thatvarious modifications are possible within the scope and spirit of theinvention as defined by the appended the claims.

What is claimed is:
 1. A medical device, comprising: a hollow housing; aneedle operable between an extended position extending forwardly fromthe housing and a retracted position in which the needle is enclosed inthe housing; a biasing element biasing the needle toward the retractedposition; and a lever mounted on the housing, pivotable between a lockedposition and an unlocked position; a guide wire projecting through thelever and the needle, wherein the wire engages the lever to prevent thelever from pivoting into the unlocked position; wherein inserting theguide wire into a patient releases the lever from the guide wirewhereupon the lever pivots into the unlocked position and the biasingelement propels the needle rearwardly into the housing.
 2. The medicaldevice of claim 1 wherein the lever includes an exposed manuallyoperable surface that can be engaged by the user to delay retraction. 3.The medical device of claim 1 comprising a fluid chamber in fluidcommunication with the needle.
 4. The medical device of claim 1 whereinthe lever is fixedly connected to the housing.
 5. A method for insertinga guide wire into a patient, comprising the steps of: providing a devicehaving a housing, a needle, a needle retainer for releasably retainingthe needle so that the needle projects forwardly from the housing, and aguide wire releasably engaging the needle retainer; inserting the guidewire into the patient so that the guide wire is displaced out ofengagement with the needle retainer; and automatically retracting theneedle into the housing upon disengagement of the guide wire from theneedle retainer.
 6. The method of claim 5 comprising the steps of:selectively manually engaging the needle retainer to impede retractionof the needle; releasing the selective manual engagement with the needleretainer to disengage the needle retainer and the needle.
 7. A medicaldevice, comprising: a hollow housing; a needle having a sharpened tipoperable between an extended position extending forwardly from thehousing and a retracted position in which the needle is enclosed in thehousing; a biasing element biasing the needle toward the retractedposition; and a needle retainer releasably retaining the needle againstthe bias of the biasing element; a guide wire projecting through theneedle for insertion into a patient; wherein the needle retainer iscooperable with the guide wire, such that disengaging the guide wirefrom the needle retainer causes the needle retainer to be automaticallydisplaced into the unlocked position, which releases the needle so thatthe biasing element displaces the needle rearwardly so that thesharpened tip is shielded against inadvertent contact.
 8. The medicaldevice of claim 7 wherein the needle is displaced rearwardly so that thesharpened tip is enclosed within the housing.
 9. The medical device ofclaim 7 wherein the needle retainer is a radially deformable arm. 10.The medical device of claim 7 wherein the needle retainer is integrallyformed with the housing.
 11. The medical device of claim 7 wherein thedevice is configured such that the guide wire can be inserted into thepatient while the needle is inserted in the patient.